Assessing Habitat Occupancy of Tiger Prey in the Hukaung Valley of Northern Myanmar

Duration

September 2012 - May 2014

Narrative

We used results from camera traps set for tigers (Panthera tigris) during 2001-2011 in the Hukaung Valley Wildlife Sanctuary of northern Myanmar to assess overall diversity of large mammal and bird species, and to identify differences in photo rates inside and outside of the most protected core area of the Sanctuary. A total of 403 camera stations were deployed during October-July in the dry seasons of 2001-2011, 260 inside the Core area and 143 Outside. From 10,750 trap-nights I obtained 2,077 independent photos of wildlife species and 699 of domestic animals and humans, including 35 species of wild mammals (19 carnivores, 4 primates, 1 elephant, 6 even-toed ungulates, 1 pangolin, and 4 rodents) and 16 species of wild birds. Of these, 1 is considered critically endangered, 7 are endangered, 11 are vulnerable, and 5 are nearly threatened. Some species that probably occur in the Sanctuary (e.g., arboreal or semi-aquatic mammals) were not photographed, likely because of camera placement. In total, 48 wild species were photographed in the Core area vs. 33 outside of the core area. No photos of any domestic animal species or insurgents were obtained inside the Core area but many more photos of poachers and villagers, but also park rangers, were obtained there. Increased patrol efforts likely helped maintain species presence in the Core area, but differences in photo rates between areas were likely influenced by differences in elevation, slope, density of streams, trails, and roads, and perhaps vegetative cover type. Tiger abundance was most influenced naturally by prey availability and anthropogenically by poaching. In the Hukaung Valley Wildlife Sanctuary in northern Myanmar, a major conservation area established to protect tigers, tiger presence has declined. This study was conducted to assess habitat occupancy and distribution of principal tiger prey species in the Core part of the Sanctuary by surveying for sign on 1651 km partitioned into 554 sampling units during November 2007 and May 2008. Using a standard occupancy model in the program PRESENCE (6.2), habitat occupancy and detection probabilities were predicted and the best candidate model for each species was selected using the Akaike Information Criterion (AIC). By incorporating 7 environmental and 5 social covariates, the predicted habitat occupancy rates were 0.76 (SE=0.196, naïve estimate = 0.5162) for gaur (Bos gaurus), 0.91 (SE=0.03, naïve estimate = 0.7762) for sambar (Rusa unicolor), 0.57 (SE = 0.003, naïve estimate = 0.3195) for wild pigs (Sus scrofa) and 0.89 (SE = 0.001, naïve estimate = 0.7996) for muntjac (Muntiacus muntjak). Overall, shorter Euclidean distances to ranger stations and trails, decreased stream density, and broadleaved evergreen/semi-deciduous forest and relatively rare rain-fed cropland habitat occurrence positively influenced prey habitat occupancy; conversely, shorter Euclidean distances to villages, roads, and streams, higher elevations, and occurrence of mixed broadleaved and needle-leaved forest habitat negatively influenced occupancy. In addition, Euclidean distance to ranger stations, trails, and roads positively affected species detections, whereas shorter Euclidean distance to villages and streams, high elevations, and high precipitation negatively affected detections. Results indicate that all four prey species were relatively abundant and well-distributed through the Sanctuary Core area and likely not a factor limiting tiger abundance.